Sounds Of The Sea
Sometimes, when I’m in the ocean, I like to lay on my back with my ears submerged and the resulting quiet is peaceful. But that doesn’t mean that the ocean is noiseless. In fact, there are many sounds in the deep blue sea, we humans just aren’t made to hear them very well… until the invention of the hydrophone – basically a microphone made for recording underwater. Suddenly the sounds of the sea came into focus. So what can we hear by recording sound underwater, by recording right off the coast of San Diego? This, is Rad Scientist. Where the scientist becomes the subject. Audio Margot: Alright, let’s stick a microphone in. Margot: Outside Scripps pier, two women wade into the water with a hydrophone and some headphones. Audio Margot: So you’re dangling it like you’re going fishing for sound. Goldie: Yes, kind of. Margot: I’m fishing for sound with Goldie: Goldie Phillips, I am a postdoc at UCSD, Margot: She’s a researcher in the Marine Bioacoustics Lab at the Scripps Institution of Oceanography studying the sounds that marine mammals make. I’m hoping that we can hear a marine mammal while recording in the surf. But what we hear sounds more like this. Audio Margot: It’s like bloop bloop bloop. Goldie: Yea, you’ll hear bubbles. You’re hearing like the waves. Margot: By Scripps Pier, the water is so shallow that all we hear are waves and bubbles. When you get further off shore and deeper, you start to capture a soundscape rich with aquatic life. These sounds can tell you a lot about marine mammals: their lifestyle, their population size, their modes of communication. These are the things that Goldie wants to know because she has been in love with the water and the creatures within it for as long she can remember. She grew up around water, in Trinidad and Tobago. Goldie: So my country being a Caribbean Island. Um, I was always, I always I grew up like always being fascinated with the ocean. I was really determined to be a marine biologist. I know a lot of people say they want to be a marine biologist in highschool but then they get to college and say that’s not going to work. But I kind of like, I was really determined to be a marine biologist. Margot: But not everyone understood her life plan. Marine biology isn’t a very common career in Trinidad and Tobago, and when she told her parents that she wanted to study marine mammals for her PhD at Duke… Goldie: It did not go well.. My dad wanted me, I’m like the first person in my family to go to college. And I am the only person in my family to get a P.H.D. So my father wanted me like I guess he put all his hopes on me and he wanted me to be like a medical doctor or like a lawyer because that's was the thing to do. So he didn't, he wasn’t very accepting of it. I think it was only when I got the Fulbright scholarship and I was the only one from my country to get this particular kind of scholarship it was like three years of science and technology. It was only when that happened and I was like OK DAD I'm leaving bye, I’m like going to do my PHD and he was like OK I think that’s when he started to come around. And he’s like oooh this is kind of cool you know. So that was kind of nice. .... Margot: Goldie starts doing internships studying marine biology. It’s at the end of one of these internships when she figures out what she wants to do with her graduate studies. She’s in the Bahamas when she sees a pod of spotted dolphins. They look like bottlenose dolphins but with tiny specks of white and grey on their backs. But Goldie notices something else about these sea creatures. Goldie: I saw like firsthand their dorsal fin is all mangled because of some strike with a boat. Margot: It’s one thing to hear about how we negatively impact wildlife and another thing to see it in person. Goldie knew she wanted to have a positive impact. Goldie: You know, That was a real, eye opening experience for me because that was when I really understood fully like how negatively humans, um, could be impacting marine mammals. We are causing, you know we're threatening the you know lives of like these animals really you know destroying their habitats and I think we also have a responsibility to do something about it. And that was when I decided that I wanted to do something in conservation. Margot: She does her part by tracking the populations of the two largest mammals on the planet. Goldie: So the two species that I’m working on are the blue whales and the fin whales. Both of them are endangered species. Those are the ones that you know have the most to lose, so that’s why I’m focusing on those. Margot: Blue and fin whales were very popular with whale hunters because of their size. Their meat was eaten and their blubber was rendered into oil. Whale hunting was outlawed in the 70’s and 80’s, but by then their populations were decimated. It will take years to recover. These whales only reach sexual maturity around 7 years of age, and their gestation is even longer than ours at around 11 months. They only give birth to one calf at a time and then wait a few years until the next. You can imagine who important it is to keep track of these species that are so endangered. And you’d think that the two largest mammal species would be easy to track. But the ocean is a big place. So you want a signal that says “whale here” that travels very far. Like this: [Blue Whale Sound] That’s the call of a blue whale sped up 10x. They make sounds to communicate with each other and search for food. And Goldie eavesdrops on the ocean listening for these whale sounds. When she hears this call, [Fin Whale Sound], she knows it is a fin whale. So how does Goldie eavesdrop on the ocean? As I found out earlier, just dropping a hydrophone off the shore isn’t going to yield much success for counting whales. Goldie makes recordings of the ocean with heavy devices deployed on the sea floor in different locations around the Pacific. Goldie and colleagues deploy and collect these devices every once in a while and I ask to tag along next time Goldie goes out to sea. She said she won’t be collecting her devices for a while, so she invites me on a trip with a colleague who studies creatures less glamorous than whales: fish. Stick around after the break to learn what it’s like to be aboard a research vessel. I wake up at 6 AM groggy, pop a couple Dramamine and drive to Point Loma to board a Scripps Research Vessel. I’m pretty out of my element on the ship. My feet are normally firmly planted on solid ground. So, it makes me feel better when we get some safety training. First lesson is about the alarm sounds the ship might make like this one [ship horn sound] ...which can mean one of two things. Crewman: Fire or Pirate….It’s most likely gonna be fire. Abandon ship is like 7 1234567, don’t bother counting, it’s like man over, no, abandon ship, get the hang off this boat, now, something like that anyways, bah bah bah bah get off. Margot: Next I get a tour from Goldie of the ship, the whole 1500 square feet of it. Goldie: We are on the R/V Sproul. Margot: The ship is named after a former Scripps Researcher. It’s been in use since 1981. Goldie: This is the wet lab, which as you can tell from the name, can get pretty wet. This is best room.. This is the dry lab, which is air conditioned so ya for that. Margot: Then on to the bathrooms, or as boat people call them Heads. Audio Margot: “Why are they called heads?” Goldie: I have no idea. I feel like on boats there is this separate dictionary that is specifically for boat terms. Margot: Trawl, Heads, Winch. The Winch is pretty essential to the whole operation of getting hydrophones to the sea floor. Goldie: A Winch is just a system you can use to deploy really heavy instruments, or to retrieve heavy instruments which we need to do for the big deployments. Margot: The day aboard the Sproul is spent traveling to different locations off the San Diego Shore, deploying instruments off the back of the ship, then moving to the next destination. We spot playful sea lions and watch birds dive for fish. We eat meals in shifts and talk about graduate school. Perhaps the most exciting moment is when the captain approaches us with a picture on his iphone. Captain: Look at that, it was on our depth sonar, so something large swam under us… Woah, that’s fairly substantial Yeah That’s not gonna be any kelp right that’s way too big No, bigger than that. Margot: It’s a USO, unidentified swimming object that I like to imagine was one of Goldie’s blue or finned whales. [music bed] It’s dark now and everyone is sleepy. 15 hours at sea will do that to you. This was a short expedition though. Other expeditions can take weeks. But there is a common thread. At some point the researchers return to land with lots of data, hours of sound, and they retreat to their computers to make sense of it all. When Goldie listens to the data, this is what she finds most of the time. [Commercial Boat Sound] Goldie: So like boats which is actually the most pervasive sounds in the ocean. Margot: Goldie and other whale conservationists worry about the ever increasing boat traffic. Not just because of the boat strikes, but also the sound they make. Goldie: So this is a large commercial ship. [More Boat Sound] Margot: Marine mammals depend on sound just to live--they use it to find mates and to find food. The ship sounds can drown out the whale calls – cutting off one of their main modes of communication with each other. [ship sounds and whale calls to demonstrate] Ship sounds are pervasive, but there are even louder sounds that can have been known to negatively affect whales. [Sonar sound] Goldie: So sonar was also a huge issue. Because it tends to be a really loud intense signals which can damage the hearing and it has been associated with like mass stranding of marine mammals. Um, before like there was like a few years ago well several years ago there was this like a mass stranding of beaked whales in the Bahamas right after like time of like navy exercises.: Margot: Hundreds of beaked whales and Minke whales were stranded in 2000 in the Bahamas after a navy exercise involving sonar. It’s just another way in which our human progress, our technology can have unexpected negative effects on the other inhabitants of our planet. Noise pollution can be just as deadly as other, more obvious forms of pollution. https://www.frontiersin.org/articles/10.3389/fmars.2017.00295/full …. Margot: It takes awareness of the ways in which we negatively impact other species and constant monitoring of these species to make sure that we can hold onto biodiversity. Goldie’s work estimating the abundance of marine mammal populations helps conservation groups monitor the status of endangered species like the fin and blue whales. So Goldie will be keeping her ears to the water to hear the calls- the whistles the songs- that make it through the ship noise. She hopes the calls will increase, because that means the whales are coming back. ….. Margot: This week’s moment of xenopus is oyster toadfish, or cryptic message? [Sound] Audio Margot: That sounded like someone talking almost Goldie: I don't know anybody who talks like that! Margot: Turns out that was an oyster toadfish. Do you know a sound from nature that’s weirder than the oyster toadfish? Tweet me your pick @RadScientistPod or email me at firstname.lastname@example.org. I want to hear all the weird sounds. If you want to hear more about Goldie’s research, you can see her give a talk about Whale Calls at the Birch Aquarium on the evening of February 11th. Part of the perspectives lecture series, It’s free to members and a small fee for non members. You can find out more and RSVP on the birch aquarium website. Rad scientist is produced by me, Margot Wohl. This episode was written by myself and Jill Jainero. Our theme guitar riff is by Grant Fisher. Logo by Kyle Fischer, no relation. Music for this episode was by Cullah, Simon Mathewson, and Andrew kn. At KPBS, Emily Jankowski is technical director, Melanie Drogseth is program coordinator, Jill Linder is programming manager, Kinsee Morlan is Podcast Coordinator, Lisa Jane Morrisette is Operations Manager, and John Decker is director of programming. This program is made possible in part by the KPBS Explore local content fund. If you liked this episode, tell a friend or rate and review us on itunes. It really helps. Thanks for listening and stay rad.